在 R 中的 ggplot 条形图上显示百分比

Question

我需要在 R 的条形图条形上显示百分比值。

此代码绘制分类数据，类别在 x 上，% 在 y 上。如何修改它，使其在条形本身上显示百分比，而不仅仅是在 y 轴上？

ggplot(data = iris) + 
geom_bar(mapping = aes(x = Species, y = (..count..)/sum(..count..), fill = Species)) +
scale_y_continuous(labels = percent)

Answer 1

ggplot 中的..count..帮助程序可能适用于简单情况，但通常最好先在适当的级别聚合数据，而不是在 ggplot 调用中聚合数据：

library(tidyverse)
library(scales)
irisNew <- iris %>% group_by(Species) %>% 
summarize(count = n()) %>%  # count records by species
mutate(pct = count/sum(count))  # find percent of total
ggplot(irisNew, aes(Species, pct, fill = Species)) + 
geom_bar(stat='identity') + 
geom_text(aes(label=scales::percent(pct)), position = position_stack(vjust = .5))+
scale_y_continuous(labels = scales::percent)

vjust = .5使每个条形中的标签居中

Answer 2

ggplot(data = iris, aes(x = factor(Species), fill = factor(Species))) +
geom_bar(aes(y = (..count..)/sum(..count..)),
position = "dodge") + 
geom_text(aes(y = (..count..)/sum(..count..), 
label = paste0(prop.table(..count..) * 100, '%')), 
stat = 'count', 
position = position_dodge(.9), 
size = 3)+ 
labs(x = 'Species', y = 'Percent', fill = 'Species')